On the path to personalization

This post from the New York Times‘ Open blog talks about the architecture and algorithms underpinning its content-personalization engine. Its experience speaks to some larger trends around companies moving from batch to stream processing and to cloud services overall. The Times’ recommendation engine used to rely on MapReduce jobs that ran every 15 minutes, but now relies on a homegrown real-time system. It used to run on Cassandra, but now runs on Amazon’s DynamoDB service.